The invention relates to a contact-making device for connecting a conductive line to a conductive film. More particularly, the present invention relates to a connective arrangement for a keyboard.
In the circuitry of electronic devices, not only the geometrical properties of the housing which accommodates the circuit have to be taken account of, but often also different technologies in the case of individual components and assemblies. A modular design, for example, conforms well with these different demands, even when it is a matter of essentially standardized and related functional groups, because one or the other circuit component, if required, can be easily separated or replaced with another similar or changed assembly. In addition, different production methods can be used depending on the technology used for the individual assemblies.
As is known, this modular design, however, also has the result that contact-making devices and possibly line connections have to be present on the connection points of the individual assemblies and functional units.
To counteract the outlay, connected therewith, in terms of multiple-plug connections the connector strip is saved, for example, in the case of printed circuit boards and replaced by parallel conductor tracks which are passed out to an outer edge and can make direct contact with the contact springs of a plug-on female strip connector. From there, a cable which is connected to the female strip connector leads to the plug connections of another assembly or to the external equipment plug.
Another measure for cost reduction consists in assigning the cable to one of the assemblies and fastening it thereto directly, that is to say without releasable plug connection. Nevertheless, directly fitting a cable to an assembly requires high outlay in terms of production, which often offsets the costs of the saved plug connection. In the case of conductor films which make possible a flexible conductor guidance similar to a cable, the functions of printed circuit board and cable can, on the one hand, be united in an ideal manner because a part of the conductor film can be provided with parallel conductor tracks which preferably end in a tab attachment of the conductor film so that this part assumes the function of a connecting cable. On the other hand, problems are created by the subsequent contact-making with a plug because the flexible tab attachment makes it considerably more difficult to plug on a female strip connector non-positively, in contrast to a rigid male connector strip.
For this reason, a device is already known which has a longitudinal rib which pushes the tab attachment out of the plane of the conductor film in the shape of an arc and against which the tab attachment nestles when the contact plug is plugged on (EP-A-0 284 855). Since the female strip connector of the contact plug is plugged on against the free end of the tab attachment, there is a substantial risk that the plug and the free tab end can jam.